Embodiments of the disclosure relate to capacitors. More particularly, embodiments of the disclosure relate to a film capacitor having a thermally conductive support and a method of forming the film capacitor.
Capacitors, such as, film capacitors, are often found in numerous electronic circuits. In some applications, these capacitors are subject to increased temperatures caused due to an external environment, ripple current pulses, or both. For example, some commercially available capacitors that are capable of handling higher voltage ratings (for example, 250 Volts DC to 1000 Volts DC) may suffer from low temperature ratings and difficulty in heat removal. For a given ambient condition, an internal temperature of a capacitor may increase by a few hundred degrees Celsius, depending on the ripple current being handled by a capacitor. For example, a polypropylene capacitor in a DC-biased ripple filter application, experiences approximately a 30° C. rise at 35 average root means square (ARMS) Ampere current with an AC sinusoidal source of 5 kHz voltage applied across the capacitor at room temperature.
Sometimes, exposure to such steep temperature rise degrades performance of the capacitors. In certain cases, the capacitor may fail to operate and may even burn down, thereby leading to a hazardous situation.
Various external cooling systems are currently used to maintain the capacitor and an inverter/converter system at safe temperature range. Such cooling systems may not only add considerable complexity, but may also increase system volume, weight, and cost. Continued reliance on such cooling systems to overcome the low temperature limitations of the current commercial capacitors may not meet the increasing demand for smaller, lighter, and high-power electrical systems.
Therefore, there exists a need for an improved capacitor that may be maintained at lower temperatures while working in one or both of a high temperature and a higher ripple current environment.